1. Field of the Invention
The present invention relates to dome structures which are suitable for use in structures such as multi-purpose stadiums.
2. Background of the Invention
FIG. 1 shows a conventional dome structure generally used for the domes of multipurpose stadiums, auditoriums, etc.
The dome structure comprises arch-shaped steel trusses 3 which are erected from an upper part of a stadium 1 toward its top 2. At the top 2, a compression ring 4 is provided so as to improve the adjustment of the end of each of the trusses.
Usually, the compression ring 4 is formed by respective ends of an upper chord 5 and a lower chord 6 which form the trusses 3, and a pair of rings 7 which pass through the respective ends once.
However, the dome frame having the above-described conventional construction is disadvantageous in that the effect of the compression ring 4 is insufficient. This is because when the compression ring 4 is formed by the single ring 7, the moment M.sub.1 induced by the self-load of the dome frame itself (uniformly distributed load P) is similar to the moment induced by the steel trusses 3 alone without the compression rings 4, as shown in FIG. 2.